Abstract : Students' motivation is a more and more important issue. Many pedagogues worked on this subject to propose ways to reflect on. From what I noticed during my intership, I decided to stress on solutions to overcome the lack of motivation among tenth grade (equivalent to a French "seconde") students for this subject : Prevention Health Environment. In this professional memory, the study examines the influence of setting up a project approach. Can we imagine that this measure would be a way to motivate student ? Hypotheses are that the project enhance motivation in accomplishing a task and helps to acquire knowledge. To check my hypotheses, fourteen demotivated students from a tenth grade class answered a survey before and after the project and after that they got a formative assessment. The results showed that students who participated in the project approach had developed a greater motivation to involve in a task. Furthermore, their knowledge seemed integrated better. This study also showed that group work has an impact on cooperation and atmosphere in class. The purpose of this measure is to put the student at the center of learning practices.